The present invention relates generally to a metering system and more particularly to a digital measurement and display system, operated under processor control.
Many digital display systems have been developed to overcome the inherent shortcomings of the more conventional and basic analog display systems. These inherent shortcomings derive primarily from meter inaccuracy and observer interpolation.
However, the digital display systems themselves present problems. One has been characterized as the "rolling numbers" phenomenon. Rapid variance in the input signal is detected and displayed with digital techniques; consequently the displayed value changes so quickly that it becomes useless. Further, the digital display does not tend to indicate, as well as the analog display, the direction and rate of change of the displayed state or condition.
The present invention substantially overcomes and avoids the cited problems of digital display systems. In a preferred embodiment, the present invention, a metering system, includes a signal conditioning circuit, processor and output system.
The signal conditioning system receives a state-indicating signal and responsively provides a repetitive, digital input signal compatible with the processor. It is to be understood that the type of state-indicating signal is insignificant, as the signal conditioning system provides appropriate conversion to a periodic, two-state signal.
The processor samples the digital input to determine the period thereof and manipulates the sampled data to appropriately drive the output system. The processor dynamically updates the output signal. i.e., updates in relation to the rate of change of the state-indicating system. This provides more accurate tracking and display of the state or condition under analysis.
In another embodiment of the present invention, the processor initially validates the repetitive digital input signal to suppress aberrations therein, such as noise. The processor interprets the input signal and removes thereof extraneous information.
In yet another embodiment, the output system of the present invention incorporates a group of output displays, each having a series of individual output components. The processor successively enables each output display with a first output signal and actuates a predetermined number of individual output components within each output display with a second output signal.
It is thus an object of the present invention to provide an accurate and reliable digital metering system. Another object is to provide a digital metering system wherein rapid variations in the measured condition, not indicative of true condition fluctuations, are substantially suppressed.
Yet another object is to provide a digital measurement and display system wherein the data is displayed in a linear and/or digital format. Still another object is to provide a metering system wherein digital data is outputted in serial and/or parallel. A further object is to provide a metering system wherein output update is a function of the rate of change of the condition to be displayed.
An object of the present invention is to provide an improved metering system wherein the output display is multiplexed. Still another object is to provide an inexpensive, readily manufactured metering system.
These and other objects, features and advantages of the present invention appear in the description of a preferred embodiment.